GPS (Global Positioning System) has been widely employed in many applications such as AVL (Automatic Vehicle Location) and AVM (Automatic Vehicle Monitoring) mounted in a fire engine, police car, ambulance, hazardous product carrying vehicle, bus, or truck for monitoring and management purposes. GPS can be combined with a navigation system to form an AVLN (Automatic Vehicle Location and Navigation System).
An implementation of the popular AVLN comprises installing a GPS engine, a GPS antenna, an e-map, and a platform (or software) in a car, and displaying the current location of the car and related routes on an LCD (Liquid Crystal Display) or a TFT (Thin Film Transistor) LCD on the instrument board. As such, a driver can choose an optimum route to the destination by referring to the same.
For keeping up with the trend of developing multifunctional electronic products, a PDA (Personal Digital Assistant) having the feature of GPS has been commercially available recently. Scheduler, notebook, and phonebook features of the PDA can be used in an office, home, or an outdoor environment. Moreover, the PDA can be used as GPS based navigation device while driving a car. That is why the PDAs are widely used by many consumers.
Moreover, for safety reasons it is inappropriate to hold a steering wheel with one hand and hold a mobile phone with the other hand while driving. As such, it is typical that a driver couples a mobile phone to a mobile sound system. In a case of an incoming call occurred, a speaker of the sound system will amplify the ringing. Further, an immediate talking between the driver and the calling party can be amplified. Hence, the driver can talk with the calling party without holding the mobile phone with the other hand.
A well known connecting assembly has been developed for facilitating a driver to operate a mobile phone and a PDA, or view an LCD. Such connecting assembly 1 is illustrated in FIG. 1. As shown, the connecting assembly 1 comprises an arm 11, a seat 12 at one end of the arm 11 for securely coupling to and supporting an electronic device (e.g., PDA, mobile phone, or LCD TV) thereon, and a removable fastening mechanism 13 at the other end of the arm 11 for connecting to a socket of a cigar lighter of a car, the removable fastening mechanism 13 comprising a rotatable ring 131, a first conical member 132, a flexible sleeve 133, and a second conical member 134. One end of the rotatable ring 131 is coupled to the arm 11 and a threaded shank 135 is extended from the other end thereof. The threaded shank 135 is driven through the bores of the first conical member 132 and the flexible sleeve 133 into a threaded bore of the second conical member 134 for fastening.
By configuring as above, in use a driver may first insert the removable fastening mechanism 13 into the socket of cigar lighter of car. Next, rotate the rotatable ring 131 for driving the threaded shank 135 into the bore of the second conical member 134 and thus pushing the first conical member 132 toward the second conical member 134. This in turn shortens the distance between the first conical member 132 and the second conical member 134 gradually. Further, conical surfaces at both sides of the flexible sleeve 133 are pressed toward each other by the first conical member 132 and the second conical member 134. As such, the length of the flexible sleeve 133 is shortened and the diameter thereof is increased. Finally, inside of the socket of the cigar lighter is filled by the flexible sleeve 133. This can achieve the purpose of fastening the connecting assembly 1 in the socket of the cigar lighter. Therefore, using the electronic device mounted on the seat 12 by the driver can be facilitated.
However, a turning of the rotatable ring 131 will also turn both the arm 11 and the seat 12 since the rotatable ring 131 is securely coupled to the arm 11. Hence, the seat 12, in often times, cannot be rotated to an optimum position when the diameter of the flexible sleeve 133 is increased to stuff itself in the socket of the cigar lighter. This may in turn cause inconvenience in operating the electronic device. Two techniques have been proposed to adjust the seat 12 to an optimum position as detailed below.
The first technique requires a driver to turn the rotatable ring 131 until the seat 12 has reached an optimum operating angle or position. However, in often times, it may compress the flexible sleeve 133 excessively, resulting in an elastic fatigue or even crack of the flexible sleeve 133. Alternatively, it is possible that a driver cannot rotate and unfasten the rotatable ring 131 if the socket of the cigar lighter is overstuffed by the removable fastening mechanism 13, resulting in a failure of removing the connecting assembly 1 from the socket of the cigar lighter.
The second technique requires a driver to slightly turn the rotatable ring 131 until it is loosened. Next, adjust the seat 12 to an optimum operating angle or position. However, it may vibrate the connecting assembly 1 while driving on a rough road since the removable fastening mechanism 13 is not secured to the socket of the cigar lighter. As a result, an easy operation of the electronic device mounted on the seat 12 is even impossible.
Thus, it is desirable among users to provide a novel removable fastening mechanism 13 which once connected to the socket of the cigar lighter, a turning of the rotatable ring 131 will not turn the arm 11 either. As a result, it is easy to adjust the seat 12 to an optimum position, thereby enabling a driver to easily operate an electronic device mounted on the seat 12.